This invention relates generally to improvements in metal retainers for retaining tubing within a housing.
Metal retainers having arms which flex radially to allow a radially enlarged, or upset of a tube to pass through the arms are known. The arms flex radially inwardly once the upset portion of the tube passes them, and abut the upset portion, preventing tube removal. This general type of retainer is widely utilized.
It is a goal in the art that the retainer easily and quickly receive a tube, while at the same time preventing the tube from being pulled outwardly of the housing. The retainer will retain the tube in the housing until the retainer "buckles". The force required to buckle the retainer is defined herein as a "buckling force." It is desirable that the buckling force be relatively high, and constant and predictable.
It is known in the prior art to extend brace members circumferentially from the arms to provide additional strength resisting buckling, and further to provide a surface which properly positions the retainer. The prior art braces may reduce the consistency of the buckling force for the metal retainer. This is undesirable, since a consistent buckling force is sought, such that the buckling force for a particular system may be accurately predicted.
Some prior art retainers provide an insertion force resisting tube insertion which increases sharply from a relatively low force to a relatively high force. Once this high force is overcome, and the tube moves past a particular point on the retainer, the momentum of the tube carries it to a fully connected position. This is referred to as an "avalanche" type connector. This type of connector ensures that a tube is properly connected within a housing, since the operator knows the relatively high force must be encountered and overcome for the tube to be properly positioned. Once the high force is encountered and overcome, tube momentum ensures that the tube is fully positioned within the housing. Known avalanche systems are quite successful, however, it is still desired to improve upon the known systems.